1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Core driver for STw4810/STw4811 |
4 | * |
5 | * Copyright (C) 2013 ST-Ericsson SA |
6 | * Written on behalf of Linaro for ST-Ericsson |
7 | * |
8 | * Author: Linus Walleij <linus.walleij@linaro.org> |
9 | */ |
10 | |
11 | #include <linux/err.h> |
12 | #include <linux/i2c.h> |
13 | #include <linux/init.h> |
14 | #include <linux/mfd/core.h> |
15 | #include <linux/mfd/stw481x.h> |
16 | #include <linux/module.h> |
17 | #include <linux/regmap.h> |
18 | #include <linux/spinlock.h> |
19 | #include <linux/slab.h> |
20 | |
21 | /* |
22 | * This driver can only access the non-USB portions of STw4811, the register |
23 | * range 0x00-0x10 dealing with USB is bound to the two special I2C pins used |
24 | * for USB control. |
25 | */ |
26 | |
27 | /* Registers inside the power control address space */ |
28 | #define STW_PC_VCORE_SEL 0x05U |
29 | #define STW_PC_VAUX_SEL 0x06U |
30 | #define STW_PC_VPLL_SEL 0x07U |
31 | |
32 | /** |
33 | * stw481x_get_pctl_reg() - get a power control register |
34 | * @stw481x: handle to the stw481x chip |
35 | * @reg: power control register to fetch |
36 | * |
37 | * The power control registers is a set of one-time-programmable registers |
38 | * in its own register space, accessed by writing addess bits to these |
39 | * two registers: bits 7,6,5 of PCTL_REG_LO corresponds to the 3 LSBs of |
40 | * the address and bits 8,9 of PCTL_REG_HI corresponds to the 2 MSBs of |
41 | * the address, forming an address space of 5 bits, i.e. 32 registers |
42 | * 0x00 ... 0x1f can be obtained. |
43 | */ |
44 | static int stw481x_get_pctl_reg(struct stw481x *stw481x, u8 reg) |
45 | { |
46 | u8 msb = (reg >> 3) & 0x03; |
47 | u8 lsb = (reg << 5) & 0xe0; |
48 | unsigned int val; |
49 | u8 vrfy; |
50 | int ret; |
51 | |
52 | ret = regmap_write(map: stw481x->map, STW_PCTL_REG_HI, val: msb); |
53 | if (ret) |
54 | return ret; |
55 | ret = regmap_write(map: stw481x->map, STW_PCTL_REG_LO, val: lsb); |
56 | if (ret) |
57 | return ret; |
58 | ret = regmap_read(map: stw481x->map, STW_PCTL_REG_HI, val: &val); |
59 | if (ret) |
60 | return ret; |
61 | vrfy = (val & 0x03) << 3; |
62 | ret = regmap_read(map: stw481x->map, STW_PCTL_REG_LO, val: &val); |
63 | if (ret) |
64 | return ret; |
65 | vrfy |= ((val >> 5) & 0x07); |
66 | if (vrfy != reg) |
67 | return -EIO; |
68 | return (val >> 1) & 0x0f; |
69 | } |
70 | |
71 | static int stw481x_startup(struct stw481x *stw481x) |
72 | { |
73 | /* Voltages multiplied by 100 */ |
74 | static const u8 vcore_val[] = { |
75 | 100, 105, 110, 115, 120, 122, 124, 126, 128, |
76 | 130, 132, 134, 136, 138, 140, 145 |
77 | }; |
78 | static const u8 vpll_val[] = { 105, 120, 130, 180 }; |
79 | static const u8 vaux_val[] = { 15, 18, 25, 28 }; |
80 | u8 vcore; |
81 | u8 vcore_slp; |
82 | u8 vpll; |
83 | u8 vaux; |
84 | bool vaux_en; |
85 | bool it_warn; |
86 | int ret; |
87 | unsigned int val; |
88 | |
89 | ret = regmap_read(map: stw481x->map, STW_CONF1, val: &val); |
90 | if (ret) |
91 | return ret; |
92 | vaux_en = !!(val & STW_CONF1_PDN_VAUX); |
93 | it_warn = !!(val & STW_CONF1_IT_WARN); |
94 | |
95 | dev_info(&stw481x->client->dev, "voltages %s\n" , |
96 | (val & STW_CONF1_V_MONITORING) ? "OK" : "LOW" ); |
97 | dev_info(&stw481x->client->dev, "MMC level shifter %s\n" , |
98 | (val & STW_CONF1_MMC_LS_STATUS) ? "high impedance" : "ON" ); |
99 | dev_info(&stw481x->client->dev, "VMMC: %s\n" , |
100 | (val & STW_CONF1_PDN_VMMC) ? "ON" : "disabled" ); |
101 | |
102 | dev_info(&stw481x->client->dev, "STw481x power control registers:\n" ); |
103 | |
104 | ret = stw481x_get_pctl_reg(stw481x, STW_PC_VCORE_SEL); |
105 | if (ret < 0) |
106 | return ret; |
107 | vcore = ret & 0x0f; |
108 | |
109 | ret = stw481x_get_pctl_reg(stw481x, STW_PC_VAUX_SEL); |
110 | if (ret < 0) |
111 | return ret; |
112 | vaux = (ret >> 2) & 3; |
113 | vpll = (ret >> 4) & 1; /* Save bit 4 */ |
114 | |
115 | ret = stw481x_get_pctl_reg(stw481x, STW_PC_VPLL_SEL); |
116 | if (ret < 0) |
117 | return ret; |
118 | vpll |= (ret >> 1) & 2; |
119 | |
120 | dev_info(&stw481x->client->dev, "VCORE: %u.%uV %s\n" , |
121 | vcore_val[vcore] / 100, vcore_val[vcore] % 100, |
122 | (ret & 4) ? "ON" : "OFF" ); |
123 | |
124 | dev_info(&stw481x->client->dev, "VPLL: %u.%uV %s\n" , |
125 | vpll_val[vpll] / 100, vpll_val[vpll] % 100, |
126 | (ret & 0x10) ? "ON" : "OFF" ); |
127 | |
128 | dev_info(&stw481x->client->dev, "VAUX: %u.%uV %s\n" , |
129 | vaux_val[vaux] / 10, vaux_val[vaux] % 10, |
130 | vaux_en ? "ON" : "OFF" ); |
131 | |
132 | ret = regmap_read(map: stw481x->map, STW_CONF2, val: &val); |
133 | if (ret) |
134 | return ret; |
135 | |
136 | dev_info(&stw481x->client->dev, "TWARN: %s threshold, %s\n" , |
137 | it_warn ? "below" : "above" , |
138 | (val & STW_CONF2_MASK_TWARN) ? |
139 | "enabled" : "mask through VDDOK" ); |
140 | dev_info(&stw481x->client->dev, "VMMC: %s\n" , |
141 | (val & STW_CONF2_VMMC_EXT) ? "internal" : "external" ); |
142 | dev_info(&stw481x->client->dev, "IT WAKE UP: %s\n" , |
143 | (val & STW_CONF2_MASK_IT_WAKE_UP) ? "enabled" : "masked" ); |
144 | dev_info(&stw481x->client->dev, "GPO1: %s\n" , |
145 | (val & STW_CONF2_GPO1) ? "low" : "high impedance" ); |
146 | dev_info(&stw481x->client->dev, "GPO2: %s\n" , |
147 | (val & STW_CONF2_GPO2) ? "low" : "high impedance" ); |
148 | |
149 | ret = regmap_read(map: stw481x->map, STW_VCORE_SLEEP, val: &val); |
150 | if (ret) |
151 | return ret; |
152 | vcore_slp = val & 0x0f; |
153 | dev_info(&stw481x->client->dev, "VCORE SLEEP: %u.%uV\n" , |
154 | vcore_val[vcore_slp] / 100, vcore_val[vcore_slp] % 100); |
155 | |
156 | return 0; |
157 | } |
158 | |
159 | /* |
160 | * MFD cells - we have one cell which is selected operation |
161 | * mode, and we always have a GPIO cell. |
162 | */ |
163 | static struct mfd_cell stw481x_cells[] = { |
164 | { |
165 | .of_compatible = "st,stw481x-vmmc" , |
166 | .name = "stw481x-vmmc-regulator" , |
167 | .id = -1, |
168 | }, |
169 | }; |
170 | |
171 | static const struct regmap_config stw481x_regmap_config = { |
172 | .reg_bits = 8, |
173 | .val_bits = 8, |
174 | }; |
175 | |
176 | static int stw481x_probe(struct i2c_client *client) |
177 | { |
178 | struct stw481x *stw481x; |
179 | int ret; |
180 | int i; |
181 | |
182 | stw481x = devm_kzalloc(dev: &client->dev, size: sizeof(*stw481x), GFP_KERNEL); |
183 | if (!stw481x) |
184 | return -ENOMEM; |
185 | |
186 | i2c_set_clientdata(client, data: stw481x); |
187 | stw481x->client = client; |
188 | stw481x->map = devm_regmap_init_i2c(client, &stw481x_regmap_config); |
189 | if (IS_ERR(ptr: stw481x->map)) { |
190 | ret = PTR_ERR(ptr: stw481x->map); |
191 | dev_err(&client->dev, "Failed to allocate register map: %d\n" , |
192 | ret); |
193 | return ret; |
194 | } |
195 | |
196 | ret = stw481x_startup(stw481x); |
197 | if (ret) { |
198 | dev_err(&client->dev, "chip initialization failed\n" ); |
199 | return ret; |
200 | } |
201 | |
202 | /* Set up and register the platform devices. */ |
203 | for (i = 0; i < ARRAY_SIZE(stw481x_cells); i++) { |
204 | /* One state holder for all drivers, this is simple */ |
205 | stw481x_cells[i].platform_data = stw481x; |
206 | stw481x_cells[i].pdata_size = sizeof(*stw481x); |
207 | } |
208 | |
209 | ret = devm_mfd_add_devices(dev: &client->dev, id: 0, cells: stw481x_cells, |
210 | ARRAY_SIZE(stw481x_cells), NULL, irq_base: 0, NULL); |
211 | if (ret) |
212 | return ret; |
213 | |
214 | dev_info(&client->dev, "initialized STw481x device\n" ); |
215 | |
216 | return ret; |
217 | } |
218 | |
219 | /* |
220 | * This ID table is completely unused, as this is a pure |
221 | * device-tree probed driver, but it has to be here due to |
222 | * the structure of the I2C core. |
223 | */ |
224 | static const struct i2c_device_id stw481x_id[] = { |
225 | { "stw481x" , 0 }, |
226 | { }, |
227 | }; |
228 | MODULE_DEVICE_TABLE(i2c, stw481x_id); |
229 | |
230 | static const struct of_device_id stw481x_match[] = { |
231 | { .compatible = "st,stw4810" , }, |
232 | { .compatible = "st,stw4811" , }, |
233 | { }, |
234 | }; |
235 | MODULE_DEVICE_TABLE(of, stw481x_match); |
236 | |
237 | static struct i2c_driver stw481x_driver = { |
238 | .driver = { |
239 | .name = "stw481x" , |
240 | .of_match_table = stw481x_match, |
241 | }, |
242 | .probe = stw481x_probe, |
243 | .id_table = stw481x_id, |
244 | }; |
245 | |
246 | module_i2c_driver(stw481x_driver); |
247 | |
248 | MODULE_AUTHOR("Linus Walleij" ); |
249 | MODULE_DESCRIPTION("STw481x PMIC driver" ); |
250 | MODULE_LICENSE("GPL v2" ); |
251 | |